Reduces spurious large scale structure in the final map within fixed regions
specified by an external mask COM.ZERO_MASK0
"
com.zero_mask0"
, it will be used in place of
parameter "
com.zero_mask"
on the first iteration only. If no value is supplied for "
com.zero_mask0"
,
the value supplied for "
com.zero_mask"
will be used on all iterations including the first.
Setting "
com.zero_mask0"
to zero will cause no masking to be used on the first iteration.
[undef
]